The present invention relates to portable object-carrying devices generally, and more particularly to hand trucks having means for selectively adjusting spacing between opposing load-bearing gripping arms. This invention also relates to methods for selectively adjusting hand truck gripping arms.
Various object-carrying devices have been designed and implemented over the years for assisting a user in carrying and transporting objects. Most often, such objects are either too heavy or too large to be easily carried by a single user. Therefore, object-carrying devices utilizing wheels or other movement facilitators have been implemented for efficiently carrying such objects. In many applications, the object-carrying devices are used to carry a stack of objects which may not be easily manipulated to load onto the object-carrying devices. Thus, a coordinated effort from multiple users is sometimes required to properly load the objects on the object-carrying devices.
An additional difficulty in standard object-carrying devices, more commonly referred to as hand trucks, is stabilizing the loaded objects onto the hand truck. In many commonly-used designs, hand trucks incorporate a load-bearing extension of fixed dimension extending from the upright frame of the hand truck. Therefore, relatively larger or irregularly-shaped objects may be unstable when loaded onto the respective hand truck support structures. To remedy this situation, some hand truck manufacturers have developed load-engaging arms which move along various axes to thereby engage and disengage various-sized objects constituting the load. The systems developed to date, however, fail to utilize a simple and convenient means for engaging and disengaging objects with respective engaging arms.
It is therefore a principle object of the present invention to provide a convenient and efficient means for selectively engaging and disengaging various-sized objects to an object-carrying device such as a hand truck.
It is another object of the present invention to provide an object-carrying device such as a hand truck which incorporates selectively expandable and contractible engaging means for engaging objects as a load on the hand truck device, which engaging means is easily and efficiently operated by a single user.
It is a still further object of the present invention to provide a hand truck device having a plurality of gripping arms for selectively engaging desired objects, which gripping arms are slidably actuated along an axis through the use of remote actuation means.
It is a yet further object of the present invention to provide actuation means operably coupled to a plurality of gripping arms extending from a hand truck device for selectively engaging and disengaging various objects to the hand truck, wherein the actuation means may be manipulated to move the gripping arms in opposing directions to thereby accomplish expansion or contraction of the space between the gripping arms.
Another object of the present invention is to provide a user-operated expansion/contraction means operably coupled to a hand truck device for selectively engaging and disengaging one or more vehicular tires to the associated hand truck.
By means of the present invention, an improved object-carrying device such as a hand truck is provided for easily and efficiently engaging objects to the object-carrying device for transportation thereon. The hand truck device of the present invention provides a means for easily expanding and contracting the space between generally opposing gripping arms to thereby engage various objects for transport without assistance from additional hand truck device users.
One embodiment of the mobile hand truck device of the present invention includes a frame having first and second upstanding side members and one or more cross members extending therebetween, and connected to, the first and second upstanding members. The hand truck device further includes a guide support structure extending between respective lower portions of the first and second upstanding side members, and a plurality of gripping arms operably coupled to the guide support structure, with the gripping arms extending outwardly from the frame in substantially horizontally opposed relationship with one another. To move the gripping arms, expansion/contraction means operably coupled to the gripping arms are provided for slidably directing the gripping arms along the guide support structure, with the expansion/contraction means being adapted to simultaneously slide respective gripping arms in opposing directions along the guide support structure. Actuation means are further provided for actuating the expansion/contraction means, and movement facilitators operably coupled to the frame and disposed adjacent to the lower portions of the first and second upstanding side members are also provided on the hand truck device.
The mobile hand truck device may also include a first upstanding rib member disposed between the first and second upstanding side members, wherein the one or more cross members are preferably connected to the upstanding rib member for structural support of the hand truck device.
The mobile hand truck device preferably includes gripping arm guides operably coupled to both the guide support structure and the gripping arms, wherein the gripping arm guides are adapted to act as interfaces between the respective gripping arms and the guide support structure. The gripping arm guides are preferably manipulated by the expansion/contraction means through expandable arm means which are adapted to laterally extend and retract the gripping arm guides along the guide support structure. Preferably, the actuation means for actuating the expansion/contraction means includes an integrally-formed foot pedal.